The invention comprises a circular VTOL aircraft which is capable of vertical and horizontal flight by combining propulsive power from one or more central vertically mounted jet or rocket engines delivering thrust downwards to four vertical thrust vents situated at cardinal points below the engine (or engines), together with power from a jet or rocket engine (or engines) horizontally mounted on a turntable pod which is steerable through 360 degrees and is situated centrally below the vertical thrust engine (or engines).
Alternatively the horizontal engine can be replaced by a central vent (or vents) from the vertical engine which provides vectored thrust downwards to a horizontal thrust nozzle (or nozzles) attached to the turntable and steerable through 360 degrees. (via steering control in the cockpit).
The stability of the craft in the horizontal plane is achieved by variable thrust control from the four cardinal vertical thrust vents giving pitch and bank control as well as full vertical take-off and landing thrust control. Thrust from the horizontal engine provides acceleration and braking power for horizontal flight as well as directional control through 360 degrees.
With the combined use of these power configurations the aircraft can achieve rapid flight manoeuvres in all directions, including for example rapid ascent or descent using full VTOL thrust control; rapid changes in direction in the horizontal plane from forward to reverse, or from side to side, or change of direction through 90 degrees, or through 360 degrees, together with pitch and bank control, as well as spin control.
This rapid manoeuvrability in the horizontal plane combined with a high rate of ascent or descent in the vertical plane, together with inherent stability as a weapons platform is designed to make the aircraft extremely effective for military applications such as rapid personnel deployment, air-sea rescue missions, photo-reconnaissance and fighter/bomber missions. For military operations the passenger compartment area may be re-designated both for weapons payload and for additional fuel tanks in order to extend the normal operating range. Weapons/missiles can be arranged to provide 360 degrees of effective fire cover. The aircraft may be constructed using composite GRP and carbon-fibre reinforced materials, which are both strong and light in weight, and will enable the craft to exhibit a low radar profile. An air-sea rescue version of the craft would use the vectored horizontal thrust unit (without the horizontal engine) which would allow the craft to float on the sea to rescue survivors.
The Harrier VTOL fighter aircraft has a critical high-risk transition operation from vertical to horizontal flight; this critical risk is avoided in the design disclosed because vertical thrust is constant and the transition from hover to horizontal flight is immediate on application of throttle to the horizontal engine. Designed to fly with a minimum of two engines (one for vertical, one for horizontal thrust), in the event of an engine failure the second engine can be used to effect an immediate emergency landing.
The flight-deck is situated at the top centre of the craft and is supported by structural formers above the main central engine (s). As a security feature the passenger compartment is completely separate from the flight-deck and is designed within the main body of the craft, together with cargo, and fuel tanks which are positioned around the central engine (s). The circular plan shape of the craft allows for a very large fuel capacity which will enable this design to out-range the conventional helicopter/VTOL aircraft as well as to have a higher passenger and cargo carrying capacity.
A notable feature of the design is that the passenger compartment, cargo and fuel-tank loadings are all integrated into the main body of the craft which combines the function of both wing and fuselage in one inherently strong disc-shape which generates lift in forward flight, thus avoiding existing problems such as wing flutter and spar-failure associated with high loading on conventional aircraft designs.
The aircraft can be adapted for use as a rescue vehicle to secure personnel from high-rise buildings in the event of fire, because, unlike the helicopter with its vulnerable rotor, this craft is designed to butt right up to the side of a building so that personnel trapped by fire can escape directly into the passenger compartment through hatches which slide open in the upper surface of the craft.
The aircraft can also be adapted for use as a fire-fighter, particularly against forest fires, by re-designating the passenger compartment area as a very large capacity container for liquid or foam extinguishers. (With total capacity dependent on the lifting power of the engines) The extinguishing liquids can be dumped directly onto the fire from hatches in the underside of the craft or directed onto burning buildings from pressurised nozzles around the circumference of the craft.
The VTOL performance ability would enable the aircraft to take off vertically, or at 45 degrees from the ground by using both vertical and horizontal thrust together, and then make a controlled descent at a 45 degree angle of approach to the airfield runway for landing rather than the very shallow approach path used by conventional aircraft at present: this would ensure a reduction in aircraft noise levels in residential areas close to airfields. In fog, it would be possible to position the aircraft directly overhead the airfield and complete a vertical descent onto the apron. This aircraft could also operate from much smaller airfields as it would not require the 1500 metre runway used by conventional aircraft and could also use existing helicopter landing pads on land, oil-rigs and ships.
The aircraft is designed to fly with the main disc-shaped body maintaining a level horizontal attitude through all stages of flight, thereby alleviating passenger discomfort experienced during high angle pitch and bank changes experienced in conventional aircraft. Whilst changes in direction can be made by steering the turntable of the horizontal jet, the pilot will also be able to use pitch and bank trim controls as required by varying the thrust from the four vertical thrust vents.
The aircraft conforms to the aerodynamics of the disc-shape which allows minimum air resistance or drag in horizontal flight, together with lift generated by airflow over the upper surface, and maximum air resistance in descent. Therefore, with suitable power units the craft will be capable of fast horizontal flight combined with the high drag/parachute effect of the disc diameter presented against the airflow for vertical descent and landing operations.